1、介词by的用法1.意为“在旁”,“靠近”。Some are singing and dancing under a big tree。Some are drawing by the lake。有的在大树下唱歌跳舞。有的在湖边画画儿。2.意为“不迟于”,“到时为止”。Your son will be all right by supper time。你的儿子在晚饭前会好的。How many English songs had you learned by the end of last term?到上个学期末你们已经学了多少首英语歌曲?3.表示方法、手段,可译作“靠”、“用”、“凭借”、“通过”
2、、“乘坐”等。The monkey was hanging from the tree by his tail and laughing。猴子用尾巴吊在树上哈哈大笑。The boys father was so thankful that he taught Edison how to send messages by railway telegraph。孩子的父亲是那么的感激,于是他教爱迪生怎样通过铁路电报来传达信息。4.表示“逐个”,“逐批”的意思。One by one they went past the table in the dark。他们一个一个得在黑暗中经过这张桌子。5.表示“
3、根据”,“按照”的意思。What time is it by your watch?你的表几点了?6.和take , hold等动词连用,说明接触身体的某一部分。I took him by the hand。我拉住了他的手。7.用于被动句中,表示行为主体,常译作“被”、“由”等。English is spoken by many people。英语被许多人说。(即“许多人讲英语。”)动名词doing动名词相当于名词,在句子中可以做主语、宾语、表语、定语等。1.作主语Fighting broke out between the South and the North。南方与北方开战了。2.作宾语
4、Would you mind turning down your radio a little, please?请问你介意调小一点收音机的音量吗?3.作表语Babysisters job is washing,cooking and taking care of the children。保姆的工作是洗衣服,作饭和照看孩子。4.做定语a washing machine 一台洗衣机used to的用法used to 意为过去常常做某事。1.肯定句:used这个词没有人称的变化,to后面接动词原形。否定句是didnt use to。When I was a child, I didnt use t
5、o like apples。当我还是孩子的时候我不喜欢苹果。疑问形式是Did you use to?Where did you use to live before you came here?当你来这儿之前你住哪儿?2.含有used to 的句子的反意疑问句不要usednt + 主语,而用didnt + 主语。He used to smoke, didnt he?他过去常常吸烟,是吗?Yes, he did。/ No, he didnt。是的,他吸。/ 不,他不吸。被动语态被动语态由助动词be加及物动词的过去分词构成,助动词be有时态,人称和数的变化。被动语态的时态是由be的时态决定的,be
6、是什么时态,全句就是什么时态,be动词后面的过去分词不变。1.各种时态的被动语态结构如下:一般现在时的被动语态:主语+am / is / are (not)+过去分词一般过去时的被动语态:主语+was / were +过去分词现在完成时的被动语态:主语+have / has +been +过去分词一般将来时的被动语态:主语+will +be +过去分词过去将来时的被动语态:主语+would / should + be +过去分词过去进行时的被动语态:主语+was / were + being +过去分词过去完成时的被动语态:主语+had + been +过去分词情态动词的被动语态:情态动词+b
7、e+过去分词2.被动语态的用法(1)不知道或没有必要说明动作的执行者是谁,不用by+动作执行者短语。Football is played widely all over the world。全世界都广泛地踢足球。(2)强调动作的承受者。The bank was robbed yesterday afternoon。昨天下午这家银行遭到抢劫。(3)作客观说明时,常采用一种被动语态句型。It is reported that about twenty children have died of flu in the USA。据报道美国大约二十名儿童死于流感。3.主动语态的句子变为被动语态的步骤(1
8、)把原句中的宾语变为主语(2)动词改为被动形式,即be+过去分词(3)原来的主语,如果需要的话,放在by后面;如果没必要,可省略。must/could/might/can1.must(1)must 表示主观看法,意为“必须”。如:You must stay here until I come back。Must I hand in my homework right now?对must引导的疑问句,肯定回答为must,否定回答为neednt 或dont have to 。如:Must I finish my homework?No, you neednt。(2)must也可以表示有把握的推测,
9、意为“ 一定,肯定”,用于肯定句。如:The light is on, so he must be at home now。其否定形式mustnt表示“禁止,不许”。如:You mustnt play with fire。You mustnt be late。2.could(1)can的过去式,意为“能、会”,表示过去的能力。如:He could write poems when he was 10。(2)could在疑问句中,表示委婉请求的语气,此时could没有过去式的意思。如:Could you do me a favour?Could I use your pen?Yes, you c
10、an。(注意回答)3.mightmight为may的过去式。might表示推测时,表示可能性低于may(此时might没有过去式的意思),当请求讲时,比may的语气更委婉。He is away from school。He might be sick。Might I use your dictionary?4.can(1)表示能力,一般译为“能、会”,尤其指生来具备的能力。如:She can swim fast, but I cant 。(2)表示许可,常在口语中。如:You can use my dictionary。(3)表示推测,意为“可能”,常用于否定句和疑问句中,此时cant译为“不
11、可能”。如:Can the news be true?No,it cant be our teacher。He is on a visit to the Great Wall。定语从句1.定语从句的概念在复合句中,修饰某一名词或代词的从句叫定语从句。被修饰的名词或代词叫先行词,引导定语从句的词叫关系词,定语从句一般放在先行词的后面。2.定语从句的关系词引导定语从句的关系词有关系代词和关系副词,常见的关系代词包括that, which, who(宾格whom,所有格whose)等,关系副词包括where, when, why等。关系代词和关系副词放在先行词及定语从句之间起连接作用,同时又作定语从
12、句的重要成分。3.定语从句的分类根据定语从句与先行词的关系,定语从句可分为限制性定语从句及非限制性定语从句。限制性定语从句紧跟先行词,主句与从句不用逗号分开,从句不可省去。非限制性定语从句与主句之间有逗号分开,起补充说明作用,如省去,意思仍完整。4.关系代词的用法(1)that 既可以用于指人,也可以用于指物。在从句中作主语、宾语或表语。作主语时不可省略,作宾语可省略。例如:Mary likes music that is quiet and gentle。玛丽喜欢轻柔的音乐。(that作主语)The coat (that) I put on the desk is blue。我放在桌子上的那
13、件外套是蓝色的。(that作宾语)(2)which用于指物,在句中作主语、宾语或表语。作主语不可省略,作宾语可省略。例如:The building which stands near the train station is a supermarket。位于火车站附近的那座大楼是一家超市。(作主语)The film (which) we saw last night was wonderful。我们昨天晚上看的那部电影很好看。(作宾语)(3)who, whom用于指人,who 用作主语,whom用作宾语。在口语中,有时可用who代替whom。who和whom作宾语时也可省略。例如:The gi
14、rl who often helps me with my English is from England。经常在英语方面帮助我的那个女孩是英国人。(作主语)Who is the teacher (whom) Li Ming is talking to?正在与李明谈话的老师是谁?(作宾语)5.关系副词的用法(1)when指时间,其先行词表示时间,when在定语从句中作时间状语。例如:This was the time when he arrived。这是他到达的时间。(2)where指地点,其先行词表示地点,where在定语从句中作地点状语。例如:This is place where he works。这是他工作的地点。(3)why 指原因,其先行词是原因,why在定语从句中做原因状语。例如:Nobody knows the reason why he is often late for school。没人知道他为什么上学总迟到。